DESCRIPTION: (Verbatim from the Applicant's Abstract) Approximately 0.5 percent to 1.0 percent of the population suffer from some sort of epilepsy, and in 15 percent -20 percent of cases the seizure are refractory to medical treatment with anticonvulsants. Eplepsy is particularly devastating in the pediatric age group. Infants and children whose seizures are recurrent, difficult to control with anticonvulsants, and prolonged tend to have the worst prognosis in terms or cognitive development. When seizures cannot be controlled with medication, surgical treatment may be considered. The outcome of epilepsy surgery varies depending upon the type of operation performed. Of the various types of cortical resections performed, the worst results are reported in patients without MRI lesions who undergo extratemporal lobe resection ; seizure free outcome is achieverd in only approximately one-half of this group of patients despite the used of invasive intracranial electrographic monitoring. Even when an extratemporal lobe lesion is present on the MRI, surgical success remains far less thatn that of temporal lobectomy. The major goal of this proposal is to provide improve noninvasive preoperative localization of epileptogenic brain tissue in children with medically uncontrolled extratemporal lobe epilepsy who are being treated with surgical resection of the epileptic focus. We will evaluate the utility of positron emission tomotgraphy (PET) imaging of the GABA/benzodiazepine receptor complex with [11C]flumazenil (FMZ) and glucose metabolism with 2-deoxy-2 [18F} fluoro-D-glucose (FDG) to provide optimum identification of epileptogenic tissue. Three specific aims are to be addressed in this proposal: 1) To determine the extent to which FMZ and/or FDG PET foci or abnormality accurately identify brain regions of seizure onset, immediate seizure spread, frequent interictal, spiking and background slowing defined by the rating of subdural electrode recordings in both lesional and non lesional extratemporal lobe epilepsy. 2) To determine if FMZ and/or FDG PET contribute to improved surgical outcome in nonlesional extratemporal lobe epilepsy. 3) To identify patterns of FMZ abnormalities outside the primary epileptic focus which are associated with poor outcome or which are associated with good seizure control following removal of the primary epiletic focus. The overall goal of our research is to improve the success rates of extratemporal lobe resections and to increase understanding of the basic mechanisms of epileptogenesis.